Bees hold tight to reduce hive noise
Researchers have discovered bees appear to counteract hive vibrations in order to facilitate communication. Karl Gruber reports.
Effective communication is a big deal for most species, humans included. But how do you communicate effectively in the middle of a crowded and noisy spot?
Bees have come up with a clever way to deal with unwanted noise, a new study in the journal Behavioural Ecology and Sociobiology shows.
Imagine you are sitting at a bar, chatting with friends. Now imagine things start getting crowed.
“The more people are in the bar, the more background noise there is. We can compensate by talking louder, but at a certain point, you get to a point that the background noise is just so loud that you can barely talk to the person right next to you, explains Michael Smith, at Cornell University in the US, who led the new study.
Bees face a comparable problem. They “talk” with each other using vibrations. For example, when they do a waggle dance, the show is not appreciated by watchful observers, but felt through substrate vibrations in the combs.
“When a bee does a waggle dance to advertise a food site, she's actually vibrating the comb, and the bees that are following her dance can use those vibrations to get information about where they should go to forage,” says Smith.
But what happens when there are more than 20,000 bees in a hive – how then to deal with all the hubbub?
In their study, Smith and colleagues measured the vibrations in five different colonies, taking into account the number of bees present. They expected that with larger numbers in the hive, the background vibrations would simply go up proportionally. More bees should equal more vibes, mostly due to the larger numbers moving around on the comb.
But their observations revealed some unexpected results. “What we found was that the background vibrations actually decrease as the number of bees on the comb increases,” says Smith.
“So, in a sense, the comb is actually becoming ‘quieter’ as the number of bees increases.”
At first, Smith thought that the decrease in vibrations was due to the larger mass of the comb with the bees on it. “Imagine, as you add more bees to the comb, it becomes heavier, and so vibrates less,” he says.
To test this idea he added dead bees to a comb to check if the vibrations levels changed. They didn’t. “That showed us that bees are damping the comb vibrations, but they're doing it in a way that's not just their mass,” Smith explains.
So, how are they doing it? Smith thinks it has to do with the posture of the insects.
“Imagine a bee that's holding onto the comb.,” he says. “Her six legs are actually connecting different cells of comb, so she's almost like a staple connecting the different cells.”
Therefore, just by holding onto the comb, a bee could damp background vibrations, even when she’s sleeping.
“Alternatively, the bees could be actively ‘balancing’ on the comb, so they might actually be counteracting the natural vibrations, thus reducing the vibrations in the comb,” he adds.
The results show a new facet of how to deal with some of the challenges of living with thousands of individuals, all sharing the same space. Also, the clever way these bees reduce vibrations may serve as inspiration in other, very different fields.
“These findings might be applicable to cases where we need to provide additional structural support to hexagonal grids,” muses Smith.
“These grids, inspired by beeswax combs, are commonly used as a lightweight but strong packing material. We might be able to get inspiration from the bees, to figure out how to add additional strength to these grids that we use for structural support.”